From: Fiona Ebner <f.ebner@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: Re: [pve-devel] [RFC v2 kernel] backport patch to fix TSC scaling for SVM
Date: Fri, 21 Oct 2022 10:02:35 +0200 [thread overview]
Message-ID: <2e5dd520-d6b9-b6d9-fb66-148678cdd983@proxmox.com> (raw)
In-Reply-To: <20220902124409.42944-1-f.ebner@proxmox.com>
Am 02.09.22 um 14:44 schrieb Fiona Ebner:
> The following issue reported on the community forum [0] is likely
> fixed by this.
>
> In my case, loading a VM snapshot that originally was taken on an
> Intel CPU on my AMD-based host often caused problems in other VMs. In
> particular, it often led to CPU stalls, and sometimes clock jumps far
> into the future. With this backport applied, everything seems to run
> smoothly even after loading the "bad" snapshot 10 times.
>
> The backport from upstream commit 11d39e8cc43e ("KVM: SVM: fix tsc
> scaling cache logic consisted of dropping the parts for nested TSC
> scaling, which is not yet present in our kernel, renaming the constant
> for the default ratio, and some context changes.
>
> [0] https://forum.proxmox.com/threads/112756/
>
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---
>
> Changes from v1:
> * Alternative approach backporting the fix of the bad commit.
>
Ping. This still is an issue with 5.15.64-1-pve and users hit it
semi-regularly [0](likely [1])[2]. This backport still fixes it for me.
Alternatively, we can go for the revert[3] (but I didn't test the revert
with 5.15.64-1-pve yet).
[0]: https://forum.proxmox.com/threads/112756/post-505796
[1]: https://forum.proxmox.com/threads/116792/
[2]: https://forum.proxmox.com/threads/116683/
[3]: https://lists.proxmox.com/pipermail/pve-devel/2022-August/053814.html
next prev parent reply other threads:[~2022-10-21 8:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-02 12:44 Fiona Ebner
2022-10-21 8:02 ` Fiona Ebner [this message]
2022-10-21 15:24 ` [pve-devel] applied: " Thomas Lamprecht
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